Enhanced Electron-Phonon Coupling in Doubly Aligned hBN-Bilayer Graphene

The relative twist angle in heterostructures of two-dimensional materials with similar lattice constants dramatically alters the electronic properties. Here, we investigate the electrical and magnetotransport properties in bilayer graphene encapsulated between two hexagonal boron nitride (hBN) crystals, where the top and bottom hBN are rotationally aligned with the bilayer graphene with a twist angle $$\theta _t\sim 0^{\circ }$$ and $$\theta _b < 1^{\circ }$$ , respectively. This results in the formation of two moiré superlattices, with the appearance of satellite resistivity peaks at carrier densities $$n_{s1}$$ and $$n_{s2}$$ , in both hole- and electron-doped regions, together with the resistivity peak at zero carrier density. Furthermore, we measure the temperature (T) dependence of the resistivity ( $$\rho $$ ). The resistivity shows a linear increment with temperature within the range 10 to 50 K for the density regime $$n_{s1}